Provide a comprehensive definition of heterochromatin and list as many examples as you can.

Video transcript

Welcome back everyone. Here's our next question. It says the type of chrome a tin. That is not transcribed and is tightly packed is when we talk about the non transcribed tightly packed chroma tin. Um The term we're looking for is here in choice C. Hetero chroma tin. And this is distinguished from you crow metin. Um Which is not our answer. You chroma tin. Is that chrome button that contains most of the genes. It's more loosely packed and is transcribed. So we've kind of got these two types separated from each other in space. Um If you're trying to remember them for a test you might think of this prefix you which usually means something good or well done or perfect. So I think this is this is a good DNA. The DNA with the genes like the business like D. N. A. Um A. Hetero chroma tin is usually found near the centrum ears and telomeres of the chromosomes and it generally contains a lot of repetitive DNA sequences, Mostly repetitive DNA sequences. There's very few genes and it's not transcribed. Let's look at our other answer choices here we've got choice be chroma tin fiber. Well the chroma tin fibers contained both the D. N. A. And the his stones as we recall um In chromosomes. The D. N. A. Is wrapped around these histone proteins and protein fiber is made up of this D. N. A. Histone complexes. It's sort of like beads on a string. So that's not what we're looking for. Since that's the whole portion of D. N. A. And his stones all the different types and finally Choice D. Promoter. Well, a promoter obviously is just those sequences that are in a preliminary spines to to begin transcription. And it's continuous with that transcribed region. So it's definitely not the hetero combat in here. So Choice D. Is not correct. So again, the type of chromosome that is not transcribed and is tightly packed as choice C. Hetero chroma to see you in the next video.